From b8fb48d7b1df7270535dfdaec20fcad82dfc67fd Mon Sep 17 00:00:00 2001
From: Olivier Cavadenti <olivier.cavadenti@gmail.com>
Date: Wed, 1 Dec 2021 10:19:31 +0100
Subject: [PATCH] Set comment size warning limit to 1024 in MySQL

---
 .../mysql/schema/mysql-tablecompiler.js       |  5 +--
 test/unit/schema-builder/mysql.js             | 36 +++++++++++++++++++
 2 files changed, 39 insertions(+), 2 deletions(-)

diff --git a/lib/dialects/mysql/schema/mysql-tablecompiler.js b/lib/dialects/mysql/schema/mysql-tablecompiler.js
index 9765b17ec4..d3b512b370 100644
--- a/lib/dialects/mysql/schema/mysql-tablecompiler.js
+++ b/lib/dialects/mysql/schema/mysql-tablecompiler.js
@@ -42,9 +42,10 @@ class TableCompiler_MySQL extends TableCompiler {
 
     if (this.single.comment) {
       const comment = this.single.comment || '';
-      if (comment.length > 60)
+      const MAX_COMMENT_LENGTH = 1024;
+      if (comment.length > MAX_COMMENT_LENGTH)
         this.client.logger.warn(
-          'The max length for a table comment is 60 characters'
+          `The max length for a table comment is ${MAX_COMMENT_LENGTH} characters`
         );
       sql += ` comment = '${comment}'`;
     }
diff --git a/test/unit/schema-builder/mysql.js b/test/unit/schema-builder/mysql.js
index 453914aa73..9b1969d141 100644
--- a/test/unit/schema-builder/mysql.js
+++ b/test/unit/schema-builder/mysql.js
@@ -1195,6 +1195,42 @@ module.exports = function (dialect) {
       }).to.throw(TypeError);
     });
 
+    it('set comment to old comment limit (size 60+) #4863', function () {
+      const warnMessages = [];
+      client.logger = {
+        warn: (msg) => {
+          warnMessages.push(msg);
+        },
+      };
+      client
+        .schemaBuilder()
+        .createTable('user', function (t) {
+          t.comment(
+            "A big comment. If we write more than 60 characters here it shouldn't trigger any warning since mysql and mariaDB maximum length is 1024 characters. Please fix this warning, it's annoying when a migration is taking place with multiple long comments."
+          );
+        })
+        .toSQL();
+      expect(warnMessages.length).to.equal(0);
+    });
+
+    it('set comment to current comment limit (size 1024+) #4863', function () {
+      const warnMessages = [];
+      client.logger = {
+        warn: (msg) => {
+          warnMessages.push(msg);
+        },
+      };
+      client
+        .schemaBuilder()
+        .createTable('users', function (t) {
+          t.comment('big comment'.repeat(100));
+        })
+        .toSQL();
+      expect(warnMessages[0]).to.equal(
+        'The max length for a table comment is 1024 characters'
+      );
+    });
+
     it('should alter columns with the alter flag', function () {
       tableSql = client
         .schemaBuilder()